Refactor data-in-code annotations.

Use a dedicated MachO load command to annotate data-in-code regions.
This is the same format the linker produces for final executable images,
allowing consistency of representation and use of introspection tools
for both object and executable files.

Data-in-code regions are annotated via ".data_region"/".end_data_region"
directive pairs, with an optional region type.

data_region_directive := ".data_region" { region_type }
region_type := "jt8" | "jt16" | "jt32" | "jta32"
end_data_region_directive := ".end_data_region"

The previous handling of ARM-style "$d.*" labels was broken and has
been removed. Specifically, it didn't handle ARM vs. Thumb mode when
marking the end of the section.

rdar://11459456

llvm-svn: 157062

1 files changed, 42 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCParser/DarwinAsmParser.cpp b/llvm/lib/MC/MCParser/DarwinAsmParser.cpp
index 6f450682cbe..5662fea86ce 100644
--- a/llvm/lib/MC/MCParser/DarwinAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/DarwinAsmParser.cpp
@@ -14,6 +14,7 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCParser/MCAsmLexer.h"
 #include "llvm/MC/MCParser/MCAsmParser.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -56,6 +57,9 @@ public:
     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveTBSS>(".tbss");
     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveZerofill>(".zerofill");
 
+    AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDataRegion>(".data_region");
+    AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDataRegionEnd>(".end_data_region");
+
     // Special section directives.
     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveConst>(".const");
     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveConstData>(".const_data");
@@ -113,6 +117,8 @@ public:
   bool ParseDirectiveSubsectionsViaSymbols(StringRef, SMLoc);
   bool ParseDirectiveTBSS(StringRef, SMLoc);
   bool ParseDirectiveZerofill(StringRef, SMLoc);
+  bool ParseDirectiveDataRegion(StringRef, SMLoc);
+  bool ParseDirectiveDataRegionEnd(StringRef, SMLoc);
 
   // Named Section Directive
   bool ParseSectionDirectiveConst(StringRef, SMLoc) {
@@ -659,6 +665,42 @@ bool DarwinAsmParser::ParseDirectiveZerofill(StringRef, SMLoc) {
   return false;
 }
 
+/// ParseDirectiveDataRegion
+///  ::= .data_region [ ( jt8 | jt16 | jt32 ) ]
+bool DarwinAsmParser::ParseDirectiveDataRegion(StringRef, SMLoc) {
+  if (getLexer().is(AsmToken::EndOfStatement)) {
+    Lex();
+    getStreamer().EmitDataRegion(MCDR_DataRegion);
+    return false;
+  }
+  StringRef RegionType;
+  SMLoc Loc = getParser().getTok().getLoc();
+  if (getParser().ParseIdentifier(RegionType))
+    return TokError("expected region type after '.data_region' directive");
+  int Kind = StringSwitch<int>(RegionType)
+    .Case("jt8", MCDR_DataRegionJT8)
+    .Case("jt16", MCDR_DataRegionJT16)
+    .Case("jt32", MCDR_DataRegionJT32)
+    .Default(-1);
+  if (Kind == -1)
+    return Error(Loc, "unknown region type in '.data_region' directive");
+  Lex();
+
+  getStreamer().EmitDataRegion((MCDataRegionType)Kind);
+  return false;
+}
+
+/// ParseDirectiveDataRegionEnd
+///  ::= .end_data_region
+bool DarwinAsmParser::ParseDirectiveDataRegionEnd(StringRef, SMLoc) {
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return TokError("unexpected token in '.end_data_region' directive");
+
+  Lex();
+  getStreamer().EmitDataRegion(MCDR_DataRegionEnd);
+  return false;
+}
+
 namespace llvm {
 
 MCAsmParserExtension *createDarwinAsmParser() {